Switch for electrically-heated hand tools



Aug. 27, 1929. G. EATON SWITCH'FOR ELECTRICALLY HEATED HAND TOOLS 2 SheetsSheet 2 m 2% V L INVENTOR.

ATTORNEYS.

Patented Aug. 27, 1929.

UNITED STATES 1,726,428 PATENT OFFICE.

GEORGE EATON, OF BALTIMORE, MARYLAND, ASSIGNOR'TO MAY C. EATON, OF BALTI- MORE, MARYLAND.

SWITCH FOR ELECTRICALLY-HEATED HAND TOOLS.

Application led April 27, 1926. Serial No. 104,866.

This invention relates to improvements in electrically-heated hand tools such as curling irons or soldering irons.

The object of the invention is to provide a tool of the character named whereby the current to heat the same may readily be controlled by the same hand which manipulates the iron.

It is not an infrequent thing for the operator of a hand tool to lay the same down without cutting off the electric current and through oversight or being called away giving no thought to the heating tool until the same has become overheated or caused some damave.

bThe present invention is therefore designed to avoid these objections by including in its structure a means which will automatically cut off the current when the tool is released bythe hand which manipulates it.

The present invention is a direct improvement on the construction of tool shown and claimed in my application for patent for electrically heated hand tools executed by melon the 18th day of June 1925, and the invention of the present application is particularly directed to the means for controlling the current and its arrangement on the handle of the tool.

The invention is illustrated in the accompanying drawings, wherein,-

Fig. 1 shows the complete tool in side elevation.

Fig. 2 illustrates an enlarged longitudinal section through the yhandle and my improved switching means carried thereby.

Fig. 3 shows an end view of the handle.

Fig. 4 illustrates the switch member in rear view,-the conductor cap having been removed.

Fig. 5 shows a vertical longitudinal section through the switch member,-the section being taken on the line 5-5 of Fig. 4.

Fig. 6 illustrates a forward end view of the switch-member. y

Fig. 7 shows a cross-sectional detail through the switch member showing the same as it would appear if viewed on the line 7--7 of Fig. 6, and

Fig. 8 illustrates the rear end of the handle and the conductor contacts projecting therefrom.

In the drawing the numeralslO and'll designate the stationary and clamping members respectively ofthe tool, which Ain this instance is a curling iron. This structure however is merely employed for illustrative purposes and may be varie The stationary member 10, is attached to and carried by a handle 12, of insulating material which latter is preferably tapered and sllghtly larger at its rear end 13.

Through the insulated handle 12, two conductor wires 14 and 15 extend,the latter entering the stationary member 10 in which the heating element, not shown, is located.

At the rear end 13 of the handle the conductor wires are secured in cylindric contact plugs 16 and 17 which latter extend rearwardly from the handle.

A central screw-threaded bushing 18, is carried in the rear end 13 of the handle for a purpose that will presently be explained, and a shallow socket or bore 19 is also provided in the said handle-end for a purpose that will also presently be explained.

On the end of the handle 12, I mount my improved rotary switch 20, which will now be described.

This switch 20 has a socket 21 at one side which snugly receives the handle-end 13 but with sullicient freedom to permit rotation of one part with respect to the other. This socketend is illustrated in Figs. 2, 5 and 6 of the drawings and has an annular recess 22; a central shallow plug 23 and two separated segmental recesses 24 and 25 formed in said plug.

The segmental recess 24 is provided at one end with a contact plate 26 which is secured in place by means of a screw 27 that screws into one end of a long bushing 28 that passes through the switch-body 2O as shown in Fig. 2 of the drawing.

The other segmental recess 25, also has a g5 contact plate 29 at one end which is held in place by a screw 30 that enters one end of a bushing 31 which latter also passes through the switch-body.

A central screw 32 passes through the 10o switch body and screws into the central bushing 18 in thehandle-end and thereby rotatably connects said switch to the handle.

When the switch body is fitted over the handle-end, the contact plug 16 enters the seg- 105 mental slot 24, while the plug 17 will enter the other segmental slot 25.

In the annular recess 22, I locate an annular coiled spring 33 and one end 34 of this spring is inserted inthe socket or bore 19 of the 11o handle while the other end of said spring enters a bore 36 in the switch body.

By means of this spring 33 the switch-body 20 will constantly be held lin a position with the contact plugs 16 and 17 in the ends of the segmental slots 24 and 25 remote from the contact plates 26 and 29 so that said plugs and contacts will normally be held out of circuitclosing contact by means of the spring.

The outer or rear end of the switch-body 2O also has a `slight recess 37 and the'rear ends or the bushings 28 and 31 are exposed at said recess so that binding screws 38 and 39 may be screwed into said bushing-ends and connect conductor wires 40 and 41 therewith.

rIhel wires V4() and 41 pass througha cable 42 which latter is supported by the well-known spiral spring support 43 and all of these elements are confined in a cap 44, which seats in the switch Vrecess 37 and is held therein by means of two screws 45.

From the foregoing explanation it will be seen that if the handle 12 be grasped by the hand and a partial rotating movement be effected between the said handle and the switchbody 20 that such partial rotating movement will bring the contact plugs l16 and 17 into engagement with the two contact plates 26 and 29 in the segmental slots or recesses 24-25 and thus closethe circuit by establishing a connection from wire 40, through bushing 28, plate 26 and plug 16 to the conductor 14 in the handle andanother connection Jfrom wire 41, through bushing 31, plate 29 and plug 17 to the other conductor wire 15 in the handle.

This connection however will be maintainedonly so long as the switch-body 20 is held by the hand in the partially rotated or circuit-closing position against the tendency of the spring`33. The spring always .tends to open the switch so that if released by the hand, it will immediately turn to the normal or open positions.

It therefore the tool be laidv down or the grasp on the handle released, the switch will immediately open and cut 0H the current so that it the lattention of the operator is directed to something other than .the tool and the' latter is laid down, the current will immediately be cut oliq automatically.

`Having described my invention, I claim,

1. Inan electrically-heated hand ,tool` the combination with a single handle having conductors with contact devices projecting from each conductor at one end of the handle, of a body lmounted for limited rotatable movement on the endv of the handle and within reach of the hand of the operator as it grips said handle and carrying spaced contact devices to be engaged with the said conductor contacts and means interposed between the handle-end and the rotatable body to normall v hold the latter turned to a position that will keep the contact devices out of engagement.

2. In an electrically-heatedV hand tool the combination with a single handle having conductors with a contactat the end of the handle for each conductor, of a body mounted for liinited'rotatable movement on the end of the handle and within reach of the hand of the operator as it grips said handle and having contacts and conductors extending longitudinally therethrough, yielding means coacting with the handle and body to normally hold the body turned on the handle to disengage the handle conductors and contacts from the body conductors and contacts, a cable enclosing other conductors which are attached to the body conductors and a cap covering thek latter conductors.

3. In an electrically-heated hand tool the combination with a single handle having conductors therein that lead to the tool, of a reversibly rotatable body having a telescoping engagement with the end of the handle, contacts carried by the body which may be brought into engagement with the handle conductors when relative rotation between the body and handle takes place inone direction, a cap secured on the end of the body and conductors entering the cap and engaging the body-contacts.

4.v In an electrically-heated hand tool the combination with a single handle having conductors therein that` lead tothe tool, of a reversibly rotatable bodyfhaving segment recesses extending part oi"v the way only therethrough the conductors of the handle projecting into said body-recesses, contact -devices in each segmental recess of the body and each contact extending through the body from said recess, a cable enclosing wires that engage the body-contacts and a cap covering the engaged wires and body-contacts. y

5. In an electrically-heated hand tool the combination with a single handle having conductors therein that lead to the tool, of a reversibly rotatable body having segment recesses extending part of the way only therethrough the conductors of the handle projecting into said body-recesses, contact devices in each segmental recess of the body; bushings extending through the body from the said segmental recesses and said bushings being connected to the contacts in the recesses, a cable enclosing wires that engage the bushings and a cap covering the engaging wires and bushings. c

6. In an electrically-heated hand tool the combination with a single handle having conductors with contact devices projecting from each conductor at one end of the handle, of a rotatable body having an annular recess in one end with a central plug encircled by the recess sai-d plug having two segmental recesses which extend part of the way .only through the body, bushings extending through the body from the bases of said segmental recesses, contact plates in said latter recesses and connected to said bushings,-the contact devices projecting from the handle-end entering said segmental recesses so as to engage the plates therein when the body is partlally rotated and yielding means to hold the body turned so as to normally keep the conductor contacts away from the plates in the segmental recesses.

7. In an electrically heated hand tool, the combination with a single handle having electric conductors with contact devices projecting from each conductor at one end of the handle, of a body mounted for limited rotatable and reverse movement on the end of the handle and Within reach ofthe hand ofthe operator as it grasps said handle, and carrying spaced electric contact devices to be engaged with the said conductor contacts, and means interposed between the handle and the rotatable body to normally hold the latter turned to a position that will keep the contact devices out of engagement.

8. In an electrically heated hand tool, the combination with a single handle having electric conductors with contact devices projecting from each conductor at one end of the. handle, of a body mounted for limited rotatable and reverse movement on the end of the handle and within reach of the hand of the operator as it grasps said handle, and carrying spaced electric contact devices to be engaged with the said conductor contacts, and sprin means interposed between the handle and the rotatable body to normally hold the latter turned to a position that will keep the contact devices out of engagement.

9. In an electrically heated hand tool, the

combination with a single handle having electric conductors with contact devices projecting from each conductor at one end of the handle, of a body mounted for limited rotatable and reverse movement on the end of the handle and Within reach of the hand of the operator as it grasps said handle, and carrying spaced electric contact devices to be engaged with the said conductor contacts, and means tending to normally force said rotatable body to position corresponding to open condition of said contact devices, upon being released by the hand of the operator.

10. In an electrically heated, hand-manipulated curling iron, the combination with stationary and clamping members, said stationary member being provided with a single handle for manipulating the curling iron, said clamping member and handle being adapted to be simultaneously manipulated by the same hand, said handle having electric conductors with contact devices projecting from each conductor at one end ofthe handle, of a body adapted for limited forward and reverse rotatable movement on the end of the handle and within reach of the hand of the operator as it grasps said handle, said body carrying spaced electric contact devices adapted to be engaged with the said conductor contacts, for closing the circuit, and means interposed between the handle and the rotatg able body to normally hold the latter turned to a position that will keep t-he contact devices out of engagement.

In testimony whereof I affix my signature.

GEORGE EATON. 

